1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * |
4 | * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> |
5 | * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> |
6 | */ |
7 | |
8 | #include <linux/kernel.h> |
9 | #include <linux/module.h> |
10 | #include <linux/errno.h> |
11 | #include <linux/fs.h> |
12 | #include <linux/file.h> |
13 | #include <linux/stat.h> |
14 | #include <linux/string.h> |
15 | #include <linux/pagemap.h> |
16 | #include <linux/mount.h> |
17 | #include <linux/sched.h> |
18 | #include <linux/slab.h> |
19 | #include <linux/statfs.h> |
20 | #include <linux/magic.h> |
21 | #include <linux/fscache.h> |
22 | #include <net/9p/9p.h> |
23 | #include <net/9p/client.h> |
24 | |
25 | #include "v9fs.h" |
26 | #include "v9fs_vfs.h" |
27 | #include "fid.h" |
28 | #include "xattr.h" |
29 | #include "acl.h" |
30 | |
31 | static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; |
32 | |
33 | /** |
34 | * v9fs_set_super - set the superblock |
35 | * @s: super block |
36 | * @data: file system specific data |
37 | * |
38 | */ |
39 | |
40 | static int v9fs_set_super(struct super_block *s, void *data) |
41 | { |
42 | s->s_fs_info = data; |
43 | return set_anon_super(s, data); |
44 | } |
45 | |
46 | /** |
47 | * v9fs_fill_super - populate superblock with info |
48 | * @sb: superblock |
49 | * @v9ses: session information |
50 | * @flags: flags propagated from v9fs_mount() |
51 | * |
52 | */ |
53 | |
54 | static int |
55 | v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, |
56 | int flags) |
57 | { |
58 | int ret; |
59 | |
60 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
61 | sb->s_blocksize_bits = fls(x: v9ses->maxdata - 1); |
62 | sb->s_blocksize = 1 << sb->s_blocksize_bits; |
63 | sb->s_magic = V9FS_MAGIC; |
64 | if (v9fs_proto_dotl(v9ses)) { |
65 | sb->s_op = &v9fs_super_ops_dotl; |
66 | if (!(v9ses->flags & V9FS_NO_XATTR)) |
67 | sb->s_xattr = v9fs_xattr_handlers; |
68 | } else { |
69 | sb->s_op = &v9fs_super_ops; |
70 | sb->s_time_max = U32_MAX; |
71 | } |
72 | |
73 | sb->s_time_min = 0; |
74 | |
75 | ret = super_setup_bdi(sb); |
76 | if (ret) |
77 | return ret; |
78 | |
79 | if (!v9ses->cache) { |
80 | sb->s_bdi->ra_pages = 0; |
81 | sb->s_bdi->io_pages = 0; |
82 | } else { |
83 | sb->s_bdi->ra_pages = v9ses->maxdata >> PAGE_SHIFT; |
84 | sb->s_bdi->io_pages = v9ses->maxdata >> PAGE_SHIFT; |
85 | } |
86 | |
87 | sb->s_flags |= SB_ACTIVE; |
88 | |
89 | #ifdef CONFIG_9P_FS_POSIX_ACL |
90 | if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL) |
91 | sb->s_flags |= SB_POSIXACL; |
92 | #endif |
93 | |
94 | return 0; |
95 | } |
96 | |
97 | /** |
98 | * v9fs_mount - mount a superblock |
99 | * @fs_type: file system type |
100 | * @flags: mount flags |
101 | * @dev_name: device name that was mounted |
102 | * @data: mount options |
103 | * |
104 | */ |
105 | |
106 | static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, |
107 | const char *dev_name, void *data) |
108 | { |
109 | struct super_block *sb = NULL; |
110 | struct inode *inode = NULL; |
111 | struct dentry *root = NULL; |
112 | struct v9fs_session_info *v9ses = NULL; |
113 | struct p9_fid *fid; |
114 | int retval = 0; |
115 | |
116 | p9_debug(P9_DEBUG_VFS, "\n" ); |
117 | |
118 | v9ses = kzalloc(size: sizeof(struct v9fs_session_info), GFP_KERNEL); |
119 | if (!v9ses) |
120 | return ERR_PTR(error: -ENOMEM); |
121 | |
122 | fid = v9fs_session_init(v9ses, dev_name, data); |
123 | if (IS_ERR(ptr: fid)) { |
124 | retval = PTR_ERR(ptr: fid); |
125 | goto free_session; |
126 | } |
127 | |
128 | sb = sget(type: fs_type, NULL, set: v9fs_set_super, flags, data: v9ses); |
129 | if (IS_ERR(ptr: sb)) { |
130 | retval = PTR_ERR(ptr: sb); |
131 | goto clunk_fid; |
132 | } |
133 | retval = v9fs_fill_super(sb, v9ses, flags); |
134 | if (retval) |
135 | goto release_sb; |
136 | |
137 | if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) |
138 | sb->s_d_op = &v9fs_cached_dentry_operations; |
139 | else |
140 | sb->s_d_op = &v9fs_dentry_operations; |
141 | |
142 | inode = v9fs_get_inode_from_fid(v9ses, fid, sb); |
143 | if (IS_ERR(ptr: inode)) { |
144 | retval = PTR_ERR(ptr: inode); |
145 | goto release_sb; |
146 | } |
147 | |
148 | root = d_make_root(inode); |
149 | if (!root) { |
150 | retval = -ENOMEM; |
151 | goto release_sb; |
152 | } |
153 | sb->s_root = root; |
154 | retval = v9fs_get_acl(inode, fid); |
155 | if (retval) |
156 | goto release_sb; |
157 | v9fs_fid_add(dentry: root, fid: &fid); |
158 | |
159 | p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n" ); |
160 | return dget(dentry: sb->s_root); |
161 | |
162 | clunk_fid: |
163 | p9_fid_put(fid); |
164 | v9fs_session_close(v9ses); |
165 | free_session: |
166 | kfree(objp: v9ses); |
167 | return ERR_PTR(error: retval); |
168 | |
169 | release_sb: |
170 | /* |
171 | * we will do the session_close and root dentry release |
172 | * in the below call. But we need to clunk fid, because we haven't |
173 | * attached the fid to dentry so it won't get clunked |
174 | * automatically. |
175 | */ |
176 | p9_fid_put(fid); |
177 | deactivate_locked_super(sb); |
178 | return ERR_PTR(error: retval); |
179 | } |
180 | |
181 | /** |
182 | * v9fs_kill_super - Kill Superblock |
183 | * @s: superblock |
184 | * |
185 | */ |
186 | |
187 | static void v9fs_kill_super(struct super_block *s) |
188 | { |
189 | struct v9fs_session_info *v9ses = s->s_fs_info; |
190 | |
191 | p9_debug(P9_DEBUG_VFS, " %p\n" , s); |
192 | |
193 | kill_anon_super(sb: s); |
194 | |
195 | v9fs_session_cancel(v9ses); |
196 | v9fs_session_close(v9ses); |
197 | kfree(objp: v9ses); |
198 | s->s_fs_info = NULL; |
199 | p9_debug(P9_DEBUG_VFS, "exiting kill_super\n" ); |
200 | } |
201 | |
202 | static void |
203 | v9fs_umount_begin(struct super_block *sb) |
204 | { |
205 | struct v9fs_session_info *v9ses; |
206 | |
207 | v9ses = sb->s_fs_info; |
208 | v9fs_session_begin_cancel(v9ses); |
209 | } |
210 | |
211 | static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) |
212 | { |
213 | struct v9fs_session_info *v9ses; |
214 | struct p9_fid *fid; |
215 | struct p9_rstatfs rs; |
216 | int res; |
217 | |
218 | fid = v9fs_fid_lookup(dentry); |
219 | if (IS_ERR(ptr: fid)) { |
220 | res = PTR_ERR(ptr: fid); |
221 | goto done; |
222 | } |
223 | |
224 | v9ses = v9fs_dentry2v9ses(dentry); |
225 | if (v9fs_proto_dotl(v9ses)) { |
226 | res = p9_client_statfs(fid, sb: &rs); |
227 | if (res == 0) { |
228 | buf->f_type = rs.type; |
229 | buf->f_bsize = rs.bsize; |
230 | buf->f_blocks = rs.blocks; |
231 | buf->f_bfree = rs.bfree; |
232 | buf->f_bavail = rs.bavail; |
233 | buf->f_files = rs.files; |
234 | buf->f_ffree = rs.ffree; |
235 | buf->f_fsid = u64_to_fsid(v: rs.fsid); |
236 | buf->f_namelen = rs.namelen; |
237 | } |
238 | if (res != -ENOSYS) |
239 | goto done; |
240 | } |
241 | res = simple_statfs(dentry, buf); |
242 | done: |
243 | p9_fid_put(fid); |
244 | return res; |
245 | } |
246 | |
247 | static int v9fs_drop_inode(struct inode *inode) |
248 | { |
249 | struct v9fs_session_info *v9ses; |
250 | |
251 | v9ses = v9fs_inode2v9ses(inode); |
252 | if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) |
253 | return generic_drop_inode(inode); |
254 | /* |
255 | * in case of non cached mode always drop the |
256 | * inode because we want the inode attribute |
257 | * to always match that on the server. |
258 | */ |
259 | return 1; |
260 | } |
261 | |
262 | static int v9fs_write_inode(struct inode *inode, |
263 | struct writeback_control *wbc) |
264 | { |
265 | /* |
266 | * send an fsync request to server irrespective of |
267 | * wbc->sync_mode. |
268 | */ |
269 | p9_debug(P9_DEBUG_VFS, "%s: inode %p\n" , __func__, inode); |
270 | return netfs_unpin_writeback(inode, wbc); |
271 | } |
272 | |
273 | static int v9fs_write_inode_dotl(struct inode *inode, |
274 | struct writeback_control *wbc) |
275 | { |
276 | |
277 | p9_debug(P9_DEBUG_VFS, "%s: inode %p\n" , __func__, inode); |
278 | |
279 | return netfs_unpin_writeback(inode, wbc); |
280 | } |
281 | |
282 | static const struct super_operations v9fs_super_ops = { |
283 | .alloc_inode = v9fs_alloc_inode, |
284 | .free_inode = v9fs_free_inode, |
285 | .statfs = simple_statfs, |
286 | .drop_inode = v9fs_drop_inode, |
287 | .evict_inode = v9fs_evict_inode, |
288 | .show_options = v9fs_show_options, |
289 | .umount_begin = v9fs_umount_begin, |
290 | .write_inode = v9fs_write_inode, |
291 | }; |
292 | |
293 | static const struct super_operations v9fs_super_ops_dotl = { |
294 | .alloc_inode = v9fs_alloc_inode, |
295 | .free_inode = v9fs_free_inode, |
296 | .statfs = v9fs_statfs, |
297 | .drop_inode = v9fs_drop_inode, |
298 | .evict_inode = v9fs_evict_inode, |
299 | .show_options = v9fs_show_options, |
300 | .umount_begin = v9fs_umount_begin, |
301 | .write_inode = v9fs_write_inode_dotl, |
302 | }; |
303 | |
304 | struct file_system_type v9fs_fs_type = { |
305 | .name = "9p" , |
306 | .mount = v9fs_mount, |
307 | .kill_sb = v9fs_kill_super, |
308 | .owner = THIS_MODULE, |
309 | .fs_flags = FS_RENAME_DOES_D_MOVE, |
310 | }; |
311 | MODULE_ALIAS_FS("9p" ); |
312 | |